1. Technical Field
The disclosure relates to an optical resin having a high refractive index and a preparation method thereof. More particularly, the disclosure relates to a sulfur-containing resin having a high refractive index and a preparation method thereof.
2. Description of Related Art
Recently, since organic optical resins have advantages of small density, breaking resistance, and handle easiness, the organic optical resins are used as a substitute of glass and widely used for optical lenses, spectacle lenses, fiber optics, windows, and other transparent objects field. However, conventional organic optical resins also have many defects, such as a low refractive index, a large birefringence, and a higher chromatic dispersion, poor heat resistance, and poor impact resistance. For overcoming these defects, many researchers try to develop monomers and resins having a high refractive index (>1.49), optical transparency, high hardness, and high impact toughness.
An optical resin with a high refractive index is prepared mainly by introducing a functional group having a higher molar refractive index to increase the refractive index of the optical resin. Introducing a sulfur atom into monomers of optical resins is an effective way to increase the refractive index and decrease the chromatic dispersion of the optical resin.